Of course, nothing is perfect. But, as you said it yourself, this forum is a good place to get reliable info about a sportsbook. Yes, there are sites doing honest reviews, but most websites with casino ratings hardly can be trusted. What I've noticed is that they can include 3-4 really good sites in their top 10, and then put on the 2nd, or even on the first place, the shady site that paid them, and since there's no forum there, you won't see any objections.
I think mostly they post dubious sites for referral links. I do not think that such reviewers are often paid for "job". We can see paid reviews on major review sites, but their review mostly shows small problems to increase the credibility of the reviewer and the casino. It's better to look here for what the players are saying.
You made a nice and true statement. The paid review sites are into business and making money and therefore they are somethings bent to be biase in order to make more money.
They will list the few trusted ones and you will believe them that you have arrived and they will introduce the shady ones among.
When I gave up was one one review site rated 1xbit so high. It was then I became convinced about the biaseness and shady deals that are done behind the scene to deceive us.